#this doesn't answer your question

HUH

The way Luke talks about his own actions in the movie, he kind of distances himself from the responsibility for his choice. He calls it a “moment of weakness” and says he would not have actually done it, characterizing it as a passing impulse. If Ben had not woken up and seen Luke standing over him with his lightsaber drawn, it would have come to nothing.

This just comes across as Luke making excuses, to me. Most people don’t impulsively decide to kill someone, and it certainly makes no sense for a character like Luke whose arc in the OT explicitly showed him learning not to be impulsive and to use violence as an absolute last resort, all while under far greater duress than he was at that moment with Ben. (Before anyone tries to argue this point, please read my breakdown of the differences between Luke’s actions in RotJ and TLJ on this post.)

But at the same time, the fact that it is so bizarrely out of character makes it hard to think of it any other way. Luke simply would not consciously choose to kill Ben like that. It’s ultimately easier to accept the explanation that Luke wasn’t fully in control of himself, as little sense as that makes, than to accept the alternative, that he was in control and still did that.